Float for tow cables



May 14, 1963 F. E. BUCK ETAL 3,089,453

FLOAT FOR TOW CABLES Filed Dec. 21. 1961 IN VENTORS FRANCIS E. BUCK JOHN E. SMH'H TTORNEY United States Patent FLOAT FOR TOW CABLES Francis E. Buck, Philadelphia, and John E. Smith, Hatboro, Pa., assignors to the United States of America as represented by the Secretary of the Navy Filed Dec. 21, 1961, Ser. No. 161,323 5 Claims. (Cl. 114-235) (Granted under Title 35, US. Code (1952), see. 266) The invention described herein may be manufactured and used by or for the government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to floats and more particularly to variable buoyancy, low drag floats for supporting tow cables used in minesweeping operations.

In minesweeping operations where towing of submerged hydrofoil arrays in shallow water with long nonbuoyant cables is performed, the cables have a tendency to drag on the bottom and in many instances become so severely damaged that the towing operation is completely disrupted. Therefore, it is necessary to support the towing cables Within the water to prevent bottom drag.

In the past heavy metal floats have been used for the support of nonbuoyant tow cables.

These metal floats are large in size, excessive in weight, high in cost, and are subject to corrosion which reduces the life expectancy of the floats.

The present invention contemplates a lightweight, variable buoyancy, low drag float for operation either on the water surface or completely submerged in the water to a depth of 170 feet.

The present invention contemplates the use of low cost Styrofoam, or other similar commercially available products, in floats of a streamlined configuration to provide light weight and low drag. The feature of variable buoyancy is obtained by varying the amount of Styrofoam used in the float by adding or removing flat sections of Styrofoam to or from the float. Since Styrofoam does not absorb water and is not subject to corrosion, the float of the present invention is leakproof and corrosion resistant.

Since the float of the present invention has a much higher ratio of buoyancy to weight compared to previously used floats, a substantial reduction in size is obtainable.

Therefore, it is an object of the present invention to provide a lightweight, low drag float which is low in cost of construction.

Another object of the present invention is to provide a float with a variable buoyancy and having a construction which enables the float to be operated at the surface of the water or submerged in the water down to a predetermined depth.

A further object of the present invention is the provision of an easily dismantled, low cost, lightweight, low drag, variable buoyancy float to be used in supporting tow cables to prevent bottom drag which is constructed of leakproof, corrosion resistant material which has a high buoyancy to weight ratio.

Other objects and features of the invention will become apparent to those skilled in the art as the disclosure is made in the following detailed description of a preferred embodiment of the invention as illustrated in the accompanying sheet of drawing wherein like reference numerals refer to like parts and in which:

FIG. 1 is a side view, partly in sect-ion, of the preferred embodiment of the float of the present invention;

FIG. 2 is an end view of the float assembly of FIG. 1; and

showing the arrangement of the swivel assembly.

7 FIG. 3 is a view taken through section 3-3 of FIG. 1

"ice v Referring now to FIG. 1 there is shown a float 10 having a streamlined configuration to reduce drag.

A series of three inch thick Styrofoam boards 1111 through 11 are strung through an opening through the center of each on a quarter inch corrosion resistant steel rod 12. i The Styrofoam boards taper up to a maximum diameter at Styrofoam board 1111 and gradually taper down to a minimum diameter at Styrofoam board 1 1 which has a diameter less than the diameter of Styrofoam board 110 and which has a thickness of approximately two inches.

A relatively thin aluminum plate 13 is inserted between Styrofoam board 11 and tail assembly 14 which is to be more fully described hereinbelow. An aluminum alloy nose plate 15 is placed on rod 12 through a hole in its center. The whole assembly is secured together by means of nuts 16 and 17 respectively threaded on each end of rod 12. Nose plate 15 and plate 13 equally distribute the force on Styrofoam boards 11a and 11 respectively, when nuts 16 and 17 are tightened to form a rigid body.

Each of Styrofoam boards 11h, 111', and 11 have four equally spaced holes drilled therethrough. One of the holes 18a, 19a, and 20a of respective boards 11h, 111, and 11 is shown in the sectioned part of FIG. 1.

The holes of individual boards are of equal diameter. The holes of Styrofoam board 11 are somewhat smaller than those of Styrofoam board 111, and the holes of Styrofoam board 11i are somewhat smaller than the holes of Styrofoam board 11h, since the size of the holes in each board is determined by the overall diameter of each board. However, the three sets of holes are of sufiicient diameter so that, when the boards are properly aligned, each hole in a board communicates with respective holes in the other boards and together form four cavities, one of which is visible in FIG. 1.

Four relatively small holes 90 apart are radially drilled in Styrofoam board 111'. One of these holes 2111 is shown in the section of FIG. 1.

Thus, when float 10 is actually in the water supporting a cable, the cavities fill up with water via hole 21m and its counterparts to maintain the tail assembly down with I respect to the nose thereby insuring that the float will not nose down as it streams through the water.

Tail assembly 14 comprises a drilled cylindrical tube 21 to which four fins 22a, 22b, 22c, and 22d of conventional configuration are welded in a series of intermittent welds. The first series of welds are indicated by reference numerals 23a through 2311 on FIG. 2.

Tail assembly 14 further comprises four quarter sections 24 through 27 of Styrofoam which are bonded to the tail fins by means of an epoxy resin. As best seen in FIG. 1 each of the Styrofoam quarter sections continues the taper to the end of the tail assembly.

In assembling float 10 tail assembly is placed on rod 12tbrough the drilled cylindrical tube 21 against plate 13. Nut 17 is tightened to abut against the end of tube 21.

There is shown in FIG. 1 and more fully in FIG. 3 a free swiveling strap assembly 28 for attaching the float 10 to a tow cable for the support thereof.

The strap assembly as seen in FIG. 3 comprises a cylindrical tube 29 having a drilled hole 31 through which rod 12 extends. The tube 29 fully extends through Styrofoam board He through the center of gravity of float 10 and perpendicular to the plane defined by fins 22a and 2211. Each end of tube 29 has a plug 32 securedly fixed to tube 29 as by a pin 33. The external ends of the plugs 32 have a threaded bolt 34 integral 0 therewith extending in an outward direction.

straps 36 are secured on bolts 34 by a nut 37 and are freely rotatable about bolts 34.

The other ends 38 of straps 36 are securely joined as by a bolt or weld and sandwich a tab 39 which has a hole 41 drilled in one end thereof for attachment to a connecting cable for a tow cable.

The buoyancy of the float may be varied by adding or removing Styrofoam boards as required. This procedure requires changing the length of rod 12 and relocating strap assembly 28 which is easily performed due to the unique assembly of the float which lends itself to convenient dismantling.

It should be understood, of course, that the foregoing disclosure relates to only a preferred embodiment and that modifications may be made therein without departing from the spirit and scope of the invention as set forth in the appended claims.

What is claimed is:

1. A float for preventing bottom drag of nonbuoyant cables engaged in towing a body through water, comprising in combination:

a plurality of lightweight, buoyant members in juxtapositioned relationship to one another,

each of said members configured whereby said plurality of members collectively form a streamlined float,

tail means connected to one end of said plurality of members for stabilizing the float as it streams through the water,

tube means passing through the center of gravity of the float at right angles to the longitudinal axis of the float,

means connected to said tube means for supporting a cable towing a body through the water.

2. A float for preventing bottom drag of nonbuoyant cables engaged in towing a body through water, comprising in combination:

a plurality of flat, lightweight, buoyant members arranged in abutting relationship to one another,

each of said members being configured whereby said plurality of members collectively form a streamlined float,

a nose plate in abutting relationship to one end of said plurality of members,

a tail assembly in abutting relationship to the other end of said plurality of members comprising four equally spaced fins extending radially outward,

an elongated rod having external threads at each end thereof extending through said nose plate, said plurality of members, and said tail assembly,

internally threaded fastener means at each end of said rod,

strap assembly means pivotally connected to means connected to said rod at the center of gravity of the float for rotation about an axis perpendicular to said rod,

said strap assembly means including means for connecting the float to a tow cable whereby the float supports the tow cable engaged in towing a body through the water.

3. A float according to claim 2 wherein said plurality of members include water trapping means disposed aft of the center of gravity of the float for maintaining the float in a nose up attitude as the float streams through the water.

4. A float for preventing bottom drag of nonbuoyant cables engaged in towing a body through water, comprising in combination:

a plurality of Styrofoam members arranged in abutting relationship to one another,

each of said members being configured whereby said plurality of members collectively form a streamlined float,

a nose plate in abutting relationship to one end of said plurality of members,

a tail assembly in abutting relationship to the other end of said plurality of members comprising four equally spaced fins extending radially outward,

an elongated rod having external threads at each end thereof extending through said nose plate, said plurality of members, and said tail assembly,

internally threaded fastener means at each end of said rod,

strap assembly means pivotally connected to means connected to said rod at the center of gravity of the float for rotation about an axis perpendicular to said rod,

said strap assembly means including means for connecting the float to a tow cable whereby the float supports the tow cable engaged in towing a body through the water.

5. A float according to claim 4 wherein said plurality of members include water trapping means disposed aft of the center of gravity of the float for maintaining the float in a nose up attitude as the float streams through the water.

References Cited in the file of this patent UNITED STATES PATENTS 729,992 Baker June 2, 1903 1,320,604 Dame Nov. 4, 1919 2,524,863 White Oct. 10, 1950 2,652,550 Lash Sept. 15, 1953 2,784,518 Boyer Mar. 12, 1957 2,928,367 McCormick Mar. 15, 1960 FOREIGN PATENTS 440,871 Great Britain Jan. 7, 1936 771,644 Great Britain Apr. 3, 1957 

1. A FLOAT FOR PREVENTING BOTTOM DRAG OF NONBUOYANT CABLES ENGAGED IN TOWING A BODY THROUGH WATER, COMPRISING IN COMBINATION: A PLURALITY OF LIGHTWEIGHT, BUOYANT MEMBERS IN JUXTAPOSITIONED RELATIONSHIP TO ONE ANOTHER, EACH OF SAID MEMBERS CONFIGURED WHEREBY SAID PLURALITY OF MEMBERS COLLECTIVELY FORM A STREAMLINED FLOAT, TAIL MEANS CONNECTED TO ONE OF SAID PLURALITY OF MEMBERS FOR STABILIZING THE FLOAT AS IT STREAMS THROUGH THE WATER, TUBE MEANS PASSING THROUGH THE CENTER OF GRAVITY OF THE FLOAT AT RIGHT ANGLES TO THE LONGITUDINAL AXIS OF THE FLOAT, MEANS CONNECTED TO SAID TUBE MEANS FOR SUPPORTING A CABLE TOWING A BODY THROUGH THE WATER. 